        precision mediump float;
        uniform vec2 blur;
        uniform sampler2D uSampler;
        varying vec2 vTextureCoord;
        uniform vec2 uTextureSize;
        void main()
        {
            vec2 offset = blur / uTextureSize;
            vec4 col = vec4(0, 0, 0, 0);
            //设置卷积模板   此处是3*3的高斯模板
            int G[9];
            G[0] = 1;
            G[1] = 2;
            G[2] = 1;
            G[3] = 2;
            G[4] = 4;
            G[5] = 2;
            G[6] = 1;
            G[7] = 2;
            G[8] = 1;

			for (int x=0;x<3;x++){	//进行3*3高斯模板的卷积（加权求平均值）
				for (int y=0;y<3;y++){
					col+=texture2D(uSampler,vTextureCoord+vec2(x-1,y-1)*offset)*float(G[x*1+y*3]);
				}
			}
			col=col/float(16);
						
            gl_FragColor = col;
        }